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Scanning Electron Microscope Blade Edge Images

I would like to see an original Super Iridium compared to the Polsilver.

Steve, would you consider doing this if I sent you an original SI?

Thanks,

Justin

Yeah, I sure can. I'm going to try and get through all the blades I currently have first and then I'll start working on requests. I guess if you want to send me a blade to scan, PM me and we can talk. I'm going to turn these as quickly as I can, but I can't hog the instrument at work...We do have actual "work" to do in my office! :tongue_sm
 
This is very interesting. So interesting that I must subscribe to the thread. Thank you for taking the time to do this. And make sure you thank your company from us as well. :p
 

Toothpick

Needs milk and a bidet!
Staff member
Could you scan several of the same blades? For instance the Feathers, or the Personna Meds (that are rumored to go through an extra wash).
I'd be interested to see the if several of same blades are all consistent looking under the scope.
 
Could you scan several of the same blades? For instance the Feathers, or the Personna Meds (that are rumored to go through an extra wash).
I'd be interested to see the if several of same blades are all consistent looking under the scope.

I can, but I basically junk the blade when I scan them because of the way I mount them. Not a big deal with Astras and Derbys, but with blades that are 4x the price...I'd rather shave with them. :001_tongu
 
Evil4blue, can you scan two blades side by side, as in edges facing each other and very close together. It would be interesting to see two blades of same brand but different batches.

Also, would you mind explaining the tables you posted? I am not familiar with this technology and do not understand some abbreviations.

I see Feather has the highest C level, more than twice than other blades. This is interesting indeed. Your Feather image is consistent to other SEM images I have seen, and that the secondary bevel is covered by a thick layer of teflon. I believe this layer will disappear after first couple of strokes.

Thanks again.
 
Evil4blue, can you scan two blades side by side, as in edges facing each other and very close together. It would be interesting to see two blades of same brand but different batches.

Also, would you mind explaining the tables you posted? I am not familiar with this technology and do not understand some abbreviations.

I see Feather has the highest C level, more than twice than other blades. This is interesting indeed. Your Feather image is consistent to other SEM images I have seen, and that the secondary bevel is covered by a thick layer of teflon. I believe this layer will disappear after first couple of strokes.

Thanks again.

Yes, I can mount 2 blades side by side and take an overall shot of the 2 edges.

The tables are generated using an Energy-dispersive X-ray spectrometer (EDS) and shows an elemental analysis of the surface of your sample. You can learn more about it here: http://en.wikipedia.org/wiki/Energy-dispersive_X-ray_spectroscopy

C stands for Carbon, Fe - Iron, Cr - Chromium, Pt - Platinum, Si - Silicon, Ti - Titanium...so on a so forth.

The feather blade had a high level of carbon in the scan, but carbon is everywhere, so it might not really be from the blade itself but deposited on the surface during manufacturing. Stainless Steel is defined by containing >10.5% Cr and >50% Fe. Stainless is also supposed to contain less than 1.5% carbon so that makes me think that the extra carbon on the surface of the Feather blade is from dust.

As for the Super-Max, I didn't see any Titanium, regardless of what the packaging says, but these scan are weight % ratios, so Ti maybe be there, but just on a really small scale and is being dwarfed by the Cr and Fe.
 
Your Feather image is consistent to other SEM images I have seen, and that the secondary bevel is covered by a thick layer of teflon. I believe this layer will disappear after first couple of strokes.

Just to clarify, removing the visible layer of teflon may not be the whole story. Here is my understanding: I hope to learn more and correct any errors. This is mostly based on the discussion at US5985459, a Gillette patent from the 1990s.

The stuff we have seen in previous images is sintered PTFE (or a similar polyfluorocarbon or fluorotelomer). That is, the blade maker applies a mixture of PTFE and solvent, then bakes the blades at high temperature. This is supposed to bond the PTFE onto the edge. But it also creates a crust of sintered PTFE. This crust does nothing for the shave. It actually increases FTC (force to cut) for the first few strokes, until it is wiped away. This fits in with what some gents say about corking or palm stropping and getting better second shaves from some blades.

When the authors of US5985459 removed the excess coating, they found that: "The quality of the first shave obtained with blades of each of the following examples is equal to or better than the quality obtained in any subsequent shave; and the decrease in quality with successive shaves in the case of blades of each particular example is equal to or less than the decrease in quality in the case of conventional fluorocarbon polymer-coated blades manufactured without the present solvent treatment step." That is, there was still some benefit to the coating even after its visible portion had been removed.

The authors noted that silicone oil spreads on uncoated steel and does not bead. So they tried some on the experimental blades and found that it still beaded up. So they speculated that while the excess PTFE had been removed, there was still a thin layer, possibly chemically bonded to the blade. This layer was not visible in the patent images, which are labelled "magnification about 900".

Add to this to the history of uncoated stainless steel blades, which failed in the market, and it seems likely that the visible, rough-looking coatings are only part of the story. Maybe this thread will help us clear that up?
 
That is amazing to see! Thanks for filming these and for taking the time to show everyone!

I wonder if you could test something also... I'm curious if manufacturers have some sort to tolerance swing in the process that can cause blades to become less sharp the more they run their sharpening machines.

If a machine has a grinding stone.. in theory it would get smaller or maybe less aggressive as you used it. If the machines process 100k blades, the first and the last could be different?

Would there be any way you could test some of the same blades but of different lots? Say a few Personna Labs but from as different lots/years as possible?

I'd love to see if there is any noticeable difference between lots. I have always felt that some of the "YMMV" stuff with blades could be a result of difference in blades manufactured on a Monday compared to a Friday, even on the same machine.

Just an idea... but thanks again for the pictures!!
 
Thank you for the informative posts mblakele.
When I asked help with the table posted I did think anyone would consider explaining the chemical elements and their symbols/abbreviations :lol:

I will do a bit of google time before I post again. What is K-ratio, Z, A, F, Net Inte., Bkgd Inte., Inte. Error, P/B ?
Or post a link to a site where I can read a bit more.

Thanks.
 
...Would there be any way you could test some of the same blades but of different lots? Say a few Personna Labs but from as different lots/years as possible?

I'd love to see if there is any noticeable difference between lots. I have always felt that some of the "YMMV" stuff with blades could be a result of difference in blades manufactured on a Monday compared to a Friday, even on the same machine...!
I wondered the same thing, many times before, but I do not have the tools to answer these questions.
 
What is K-ratio, Z, A, F, Net Inte., Bkgd Inte., Inte. Error, P/B ?
Or post a link to a site where I can read a bit more.

I found this explanation of some terms - hope it helps: http://www.geology.wisc.edu/~johnf/empa.html

Standards and calibration: the quantitative analytical routine, in a nutshell, is in two parts: first you determine the x-ray count rate on standards (should be well characterized and homogeneous material), then you collect x-rays on your unknown usually the same conditions, and then ratio the two. That gives you the "k-ratio", which is roughly equivalent to the weight fraction of your unknown, if the standard were pure element. The second part is that there must be a matrix correction: that is, the x-rays you collect reflect several processes, with a major one being absorption as they exit the sample. This correction has several formulations, with 'ZAF'' a standard type.

For the elements, I see these:

  • C: carbon, probably from the steel.
  • Cr: chromium, from the steel and maybe a little from hardness coating.
  • Fe: iron, from the steel.
  • Pt: platinum, probably from hardness coating.
  • Si: silicon, either from the steel or from processing.

Steel always contains some carbon, and stainless always contains a fair amount of chromium. I was also expecting Mn (manganese) because Böhler Uddehom specifies their AEB-L blade steel as 0.67% C, 0.40% Si, 0.60% Mn, 13% Cr. But many of these are traces, so they may get lost in the noise.
 
Well, I hit the point in the thread where I can't edit the first post any more, so I guess these images will be scattered throughout. I wish I could keep them all together up top, but I can't seem to figure out how. Here's the last batch for today. I had time on my lunch break to do these.

I'll get some more done tomorrow or later this week.

Astra Superior Platinum:





Astra Superior Steel:





Derby Extra:





Kai:



 
Outstanding! First time I see Astra SP and it is reassuring to know they are true to their word. I can see Pt there and assume it is from coating.

Can you scan cross section? I have seen cross section images for Feather and Kai but never for Astra or other Gillette blades.

Thanks mblakele for your help. It saved me some time.
 

Toothpick

Needs milk and a bidet!
Staff member
I find it interesting the difference between all these edges! check out the Derby then the Astra. I'd much rather shave with Astra if I looked at these images first.

I can, but I basically junk the blade when I scan them because of the way I mount them. Not a big deal with Astras and Derbys, but with blades that are 4x the price...I'd rather shave with them. :001_tongu

That's understandable. Don't blame you there.
 
Outstanding! First time I see Astra SP and it is reassuring to know they are true to their word. I can see Pt there and assume it is from coating.

Can you scan cross section? I have seen cross section images for Feather and Kai but never for Astra or other Gillette blades.

Thanks mblakele for your help. It saved me some time.

Actually, I can in fact do cross-sections, but I'll have to figure out how to do a razor blade without cutting the crap out of myself.
 
I'd love to send you a brand-new, legendary Personna 74 for analysis. If you're intetested, please PM your address and I'll drop it in the mail today. I'm on shave 19 with one of them and it's still sharp as shave 1.
 
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